Once completed, the 220-story structure will surpass Burj Khalifa to become the tallest structure in the world.

The building will also outshine the 632-meter Shanghai Tower (上海中心).

BSB inked an agreement last week with authorities from Wangcheng district in Changsha, where the building will stand, but the project is still pending approval from central government.

In an interview with Xinhua, BSB chief executive officer Zhang Yue (张跃) said the company plans to break ground on Sky City in November 2012, and that the tower will be completed in January 2013.

The company is confident the government will green-light the project.

BSB is renowned for its eye-opening construction efficiency. Its portfolio includes assembling a 15-story building in six days in June 2010, and erecting a 30-story hotel in 360 hours in December 2011.

According to Chinese newspaper 21 Century Business Herald, the total investment in Sky City is RMB 4 billion (US$628 million), compared with US$1.5 billion on Burj Khalifa and US$2.2 billion on Shanghai Tower.

Getting central government approval should be a simple matter for the company that built China's Shanghai Expo 2010 pavilion.

In New York Freedom tower has already cost $3.8 billion and is not completed yet. Freedom Tower is looking at a late 2013 completion.

They plan to capture 30% of the world's construction industry, which will be achievable by dominating construction in China alone. As noted they have factories and franchisees in India and are talking to companies in many other countries. This shift will transform the skylines of the cities of the world, which is still rapidly urbanizing from 50% to 60% by 2020.

Reach for the sky: the world's tallest buildings, once the 838-meter Sky City is completed, projected for January 2013.

93% of the building materials are manufactured in the factory. The company welcomes global franchisees to adopt this model and build such factories locally. In supporting the company's value to be green, the factory should be located no more than 500km from the construction site.

Broad Group's methods reduce the work hazards faced by construction workers on the site, wastage and traffic jams around construction.

Construction companies have lower interest costs for buildings that take only a few weeks instead of two year or more.

The buildings are five times more energy efficient in operation and use about 6 times less cement.

They plan to build one hundred and fifty 30-story apartment building, hotel, office plans using the new system. They built a 1.33-million-square meter “NO.1 Sustainable Building Factory” and it produces 10 million square meters of mass produced skyscrapers (about 100 million square feet) each year. The 30 story building is 183000 square feet so the factory can produce about 500 of the 30 story building each year and many more factories will be built.

The Changsha Broad Air Conditioning Company previously unveiled designs for a 200-storey Sky City tower, a sustainable mixed use project. At 666 meters tall, the building will house 1.2 million square meters (12 million square feet) of space for residential apartments, retail, offices, restaurants, schools and a myriad of other facilities. The building will be manufactured in a factory and assembled on the construction site. Additionally, the tower will have the capacity for 70,000 to 110,000 residents. It will use 400 kilograms (1000 pounds of material) per square meter). 480,000 tons of building. Even with reducing the occupancy by half so that units are 1320 square feet instead of 660 square feet the amount of material is 12 tons per person for 40,000 people. The Broad Group building also includes offices and retail shopping. Instead of being 6 times more efficient with material it is more like 8-10 times, since it is replacing 72 tons of house and the extra buildings for offices and shops. It is 20 times more efficient if the higher occupancy levels are used.

Comfort of Skycity
• 100% fresh air, no mixed with return air, eliminate infection. 3-stage filtered fresh air , 99% nano-particulates be filtered. Indoor air is 20-100 times cleaner than outdoor air. Central vacuuming system keeps indoor air quality.
• Space blocks and all rooms remain at 20~27 ℃ all year round
• The clear height of residences and office is 2.8m, the clear height of space blocks are 5.6m, 9m, 12m respectively.
• Four 4meter wide streets start from the ground to the floor 121 at 400m, the total length of street is 12km, shops, agriculture markets, handcraft shops, restaurants, amusement parks, sports centers, natatorium, cinemas, opera houses, museums, libraries, training centers, schools, kindergartens, clinics, banks, police stations, etc. on both sides of street, same as city downtown. Botanical garden, natural parks, fishponds, waterfalls, sand beach can be found in some floors, same as the suburban.
• 16 large observation elevators and 31 high-speed elevators can serve 30,000 people every hour.

Safety
• Level 9 earthquake resistance, scale model will be tested by national authorized institution.
• BROAD unique technologies “diagonal bracing, light weight, factory-made” ensure the
highest earthquake resistance level with minimum materials.
• Trapezoidal construction structure corresponds the law of mechanics, which can withstand earthquake and storm.
• Sky gardens locate on floor 71, 121, 156, 176 and 191(12,000m2 in total), also function as the helipads, which are able to evacuate tens of thousand people during fire emergency, provide extra fire protection than conventional skyscrapers.

Energy Conservation
• 150mm exterior insulated walls, triple-paned windows, exterior solar shading, interior window insulation and heat recovery fresh air, 80% more energy efficient than conventional buildings.
• Adopting “distributed energy system”, turbines provide power independently, exhaust from turbines is the source for cooling, heating and sanitary hot water. 50% more energy efficient than the power grid.
• Indoor HVAC is controlled by occupancy sensor, fan speed will be automatically adjusted to the lowest load when people left.
• Elevator generates electricity when ascending unload and descending full load, also choose the floor outside the elevator, and other electricity saving methods can save 75% more electricity than conventional elevator.
• LED lamp, 90% more energy efficient than incandescent lamp and 50% more energy efficient than fluorescent lamp.
• Separated drainage system, rain water is used for plant irrigation, bathing water will be directly drained after settled, bathroom sewage and kitchen waste go to biogas tank, biogas is used as fuel for air conditioning, and solid wastes become organic fertilizers.

With a total construction area of over 500,000 sq m, Kingdom Tower will be a mixed-use building featuring a Four Seasons hotel, serviced apartments, office space, luxury condominiums and an observatory.

Construction, which started earlier this year, is expected to take a total of 63 months.

The contract for construction of the tower was signed with Saudi Binladen Group for SAR4.6bn (US$1.2bn) with the overall estimated cost of the Kingdom City Jeddah project projected at SAR75bn (US$20bn).